System and method for application location register routing in a telecommunications network

ABSTRACT

A system and method for application location register routing at a signal transfer point ( 26 ) are provided. The signal transfer point ( 26 ) includes processor clusters ( 64, 66, 68 ) and databases ( 236, 238 ) for processing queries including global title translation, local number portability, and application location register routing. A query message is received by the signal transfer point ( 26 ), a first database residing in the signal transfer point ( 26 ) is accessed to determine the location of a second database ( 238 ) also residing in the signal transfer point for processing the query message. The second database ( 238 ) is then accessed to obtain the network address of a home location register or short message service center, which is then used to deliver the query message to the network node specified by the network address.

RELATED APPLICATIONS

This application is a continuation of Ser. No. 09/613,440 filed Jul. 11,2000, now U.S. Pat. No. 6,574,481, which is a continuation of Ser. No.09/467,659 filed Dec. 20, 1999, now U.S. Pat. No. 6,097,960 which is acontinuation of Ser. No. 08/964,599 filed Nov. 6, 1997, now U.S. Pat.No. 6,006,098.

TECHNICAL FIELD OF THE INVENTION

This invention is related in general to the field of telecommunicationssystems. More particularly, the invention is related to a system andmethod-for Application Location Register (ALR) routing in atelecommunications network.

BACKGROUND OF THE INVENTION

Wireless or Personal Communication Service (PCS) providers have been,until recently, able to store and maintain subscriber information andcurrent location data on only one home location register (HLR). However,due to the escalating number of subscribers and the rapid expansion ofthe wireless (PCS) communications networks, it has become necessary toemploy multiple home location registers to accommodate the growth.

By using multiple home location registers in the wireless communicationsnetwork, it becomes necessary to devise a system and method to route thequery messages and location updates to the proper home locationregister. A proposed solution is to provide a database in the servicecontrol point (SCP) in the telecommunications network, which maintainsrouting information. However, a serious drawback with this solution isthe additional traffic it may cause in the signaling system no. 7 (SS7)network by routing these additional queries from the mobile switchingcenters (MSCs) to the service transfer points (STPs) and then to theservice control point. These queries add to the existing signalingtraffic that accomplish toll-free calling, number portability, and otherglobal title translation (GTT) queries to provide services such as lineinformation database (LIDB) services, switch based services (SBS) suchas certain Bellcore's CLASS® services, calling name (CNAM) delivery, andinterswitch voice messaging (ISVM). Due to the anticipated large overallquery volume, the SS7 link set between the service control point andsignal transfer point becomes a troublesome bottleneck, creating apotentially substantial negative impact to the network's ability toroute calls and provide services.

SUMMARY OF THE INVENTION

Accordingly, a need has arisen for a solution to the applicationlocation register routing problem for multiple home location registers.The teachings of the present invention provides a system and method forapplication location register routing which addresses this problem.

In one aspect of the invention, a method for application locationregister routing in a signal transfer point in a wirelesstelecommunications network is provided. The method includes the steps ofreceiving a query message requesting for information related to aspecific mobile telecommunications customer, decoding the query messageand obtaining a translation type and a global title address therefrom,looking up the translation type in a first database residing in thesignal transfer point and determining a location of a second databaseresiding in the signal transfer point for processing the query message.Thereafter, at least a predetermined portion of the global title addressis used to look up, in the second database residing in the signaltransfer point, to obtain a network address of a destination forprocessing the query message. The query message is then forwarded to anetwork node in the wireless telecommunications network specified by thenetwork address.

In another aspect of the invention, a system for application locationregister routing in a wireless telecommunications network includes afirst cluster of processors adapted for receiving a query messagerequesting for information related to a specific mobiletelecommunications customer, a first database being accessible by thefirst cluster of processors and having location information of a seconddatabase, and a second cluster of processors co-located with the firstcluster of processors and being adapted for receiving at least a portionof the query message from the first cluster of processors. The secondcluster of processors is dedicated to process application locationregister routing. A second database is accessible by the second clusterof processor and stores network addresses specifying the destinations ofthe query messages. The second cluster of processors are adapted toobtaining the network addresses from the second database and forwardingthe network address to the first cluster of processors.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, reference may bemade to the accompanying drawings, in which:

FIG. 1 is a simplified block diagram of a portion of an exemplarytelecommunications network according to the teachings of the presentinvention;

FIG. 2 is a simplified block diagram of an exemplary signal transferpoint with an SS7 application location register subsystem according tothe teachings of the present invention;

FIG. 3 is a simplified flowchart of an embodiment of an embodiment of anapplication location register process according to the teachings of thepresent invention; and

FIG. 4 is a simplified process flow diagram of an embodiment ofapplication location register as part of a global title translationprocess according to the teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiments of the present invention are illustrated inFIGS. 1—4, like reference numerals being used to refer to like andcorresponding parts of the various drawings.

FIG. 1 is a block diagram of a telecommunications network 10 forwireless call delivery and services. Telecommunications network 10 ispreferably constructed pursuant to the Advanced Intelligent Network(AIN) architecture. Telecommunications network 10 includes a number ofwireless service subscribers 12 who are in communications with a basestation (BS) 16 via a number of land-based transmission towers 14 and/orsatellite-based wireless transponders (not shown). Base station 16 maybe coupled to at least one mobile switching center (MSC) 20, which isfurther coupled to a network of mobile switching centers 20. Mobileswitching centers 20 are further coupled to a pair of signal transferpoints (STPs) 26 which each includes an application location register(SLR) subsystem. Signal transfer points 26 and mobile switching centers20 may be coupled to a public switched telephone network 22.

Telecommunications network 10 further includes service control points(SCPs) 30 that may include multiple home location register (HLR)databases. Service control points 30 may be coupled to an authenticationcenter (AC) database 32. A service management system (SMS) 40 is coupledto service control points 30, authentication center 32, a servicecontrol point having a short message service center (SMSC) database 34,and an intelligent peripheral (IP) 36. Short message service center 34may support voice mail, email, paging, and other services supported bythe mobile telecommunications network. A user interface 42 which may bea computer platform, workstation, or terminal, is coupled to servicemanagement system 40. A service creation environment (SCE) 44 is coupledservice management system 40, and also may utilize a user interface 46.

Service control points 30 and 34 are coupled to signal transfer points26 via signaling system no. 7 (SS7) link sets specified by the AmericanNational Standard Institute (ANSI). An SS7 link set may include up tosixteen 56 Kb/s links. Signal transfer points 26 are furtherinterconnected to mobile switching centers 20 via SS7 link sets.

Signal transfer points 26 of the present invention may include globaltitle translation (GTT) databases such as local number portability(LNP), line information (LIDB), switch based services, calling name(CNAM), and interswitch voice messaging (ISVM) databases containingrouting data related to each service. In addition, when the wirelessservice provider requires the use of multiple home location registers,an application location register database is needed to identify the homelocation register that maintains a particular subscriber's serviceinformation.

A telecommunications service designer may design and implement a callservice at service creation environment 44 via user interface 46. Theservice logic and database schema may then be downloaded to servicemanagement system 40 for distribution to other network components, suchas intelligent peripheral 36, service control points 30 and 34,authentication center 32, etc. System management, maintenance andadministration may be performed at service management system 40 via userinterface 42.

In telecommunications network 10, calls may originate from anon-wireless telephone customer to another non-wireless telephonecustomer, from a wireless telephone customer to another wirelesstelephone customer, from a non-wireless telephone customer to a wirelesstelephone customer, and vice versa.

Referring to FIG. 2, a more detailed block diagram of a subsystem 60 ofsignal transfer point 26 with added database and processing units forapplication location register is shown. Signal transfer point 26includes a message transport network (MTN) backbone 62 which providescommunication between clusters of processors 64–70. One cluster ofprocessors 70 may perform administration, maintenance, and communicationfunctions for system 60. Other clusters 64–68 process SS7 signalingmessages that are transmitted on SS7 link sets to signal transfer point26. SS7 cluster 64 may be designated for local number portability, forexample, which includes a transport node controller (TNC) 80 coupled tocommon channel distributors (CCDs) 84, a distributed SS7 servicesprocessor (DSS) 86, and common channel links (CCLKs) 88 via a network82. A second SS7 cluster 66 may be devoted to application locationregistration and may similarly include a transport node controller 100coupled to common channel distributors 104, a distributed SS7 servicesprocessor 106, and common channel links 108 via a network 102. System 60may include additional SS7 clusters 68 for other global titletranslation processes or routing to processors within system 60, whichmay be similarly equipped with a transport node controller 110, commonchannel distributors 114, and common channel links 116, linked togetherby a network 112. It may be seen that transport node controllers, commonchannel distributors, and distributed SS7 services processors of eachcluster are shown as processor pairs. The processor pairs may operate instandby or load sharing modes. The processors may also include faulttolerant multiprocessor engines with built-in redundancy.

Administration cluster 70 also includes a transport node controller 120coupled to an administration processor 124, a traffic metering andmeasurement (TMM) processor 126, and an ethernet controller 128.Ethernet controller 128 may be coupled to a user interface orworkstation 130 which is also coupled to service management system 40.Craft personnel may perform system maintenance and administrativefunctions via user interface 130 and administration cluster 70.

FIGS. 3 and 4 are a flowchart and a message flow diagram of theapplication location register routing process 200, respectively. An SS7query message is first routed to a common channel link 116 of SS7cluster 68, as shown in block 202 in FIG. 3. Common channel link 116forwards the query message to a common channel distributor 114 of SS7cluster 68, as shown in block 204. Common channel distributor 114 beginsSCCP (signaling connection user part) processing and looks at the TCAP(transaction capabilities application part) portion of the querymessage, as shown in block 206. This is also shown in block 230 in FIG.4. As part of the global title translation (block 232 in FIG. 4), theTCAP is decoded to determine the translation type, as shown in block208. In particular, the global title address (GTA) in the SCCP calledparty address (CdPA) part of the query message is decoded to obtain thetranslation type and a 15-digit IMSI (international mobile subscriberidentity; E.212 format) or an 11-digit MSISDN (mobile subscriberdirectory number; E.164 format) to perform the translation process.Generally, application location register routing uses the 15-digitIMSI-based addressing for mobile customer location updates, which isdesignated as translation type 9. The query messages for locationupdates are routed to the network node, typically a particular homelocation register, specified by the network address obtained in thetranslation process. MSISDN-based addressing is used for directingrequests related to the send routing information procedure forterminating calls, which is translation type 10. The query messages forsend routing information are routed to the network node (typically aparticular home location register) of the specified network addressobtained in the translation process. The forward short message requestsmay contain the MSISDN (translation type 12) or the IMSI (translationtype 13). The query messages for forward short message are routed to anetwork node, typically a short message service center, based on thenetwork address obtained in the translation process.

In FIGS. 3 and 4, based on the translation type, the location of theglobal title translation database is determined, as shown in block 210in FIG. 3 and block 234 in FIG. 4. The database location may be obtainedby referring to a lookup table or database which lists translation typesand the corresponding database identifier or location. For applicationlocation register routing queries, the database location has beendesignated to be distributed SS7 services processor 106 of SS7 cluster66, for example. Therefore, the query message or relevant portionsthereof are forwarded to distributed SS7 services processor 106 of SS7cluster 66. As shown in blocks 212 and 214, certain global title addresspreprocessing may be performed prior to forwarding the query todistributed SS7 services processor 106. For example, the global titleaddress in the called party address portion of the message may bedecoded to obtain the 11-digit MSISDN field for translation to thenetwork address of the specific short message service center. The11-digit global title address is a 10-digit NANP (North America numberplan) with a “1” prefix (e.g. 1-NPA-NXX-XXXX) or an international10-digit format with a prefix of “1” through “9.” Depending on systemdesign and implementation, the address preprocessing may further stripout one or more predetermined digits of the global title address (e.g.the leading “1”) prior to forwarding it for further processing.

In distributed SS7 service processor 106, one or more tables ordatabases 238 are searched for the IMSI or MSISDN to determine theglobal title translation destination network address for the specifiedhome location register or short message service center, or any otherservices associated with the mobile telecommunications subscription, asshown in blocks 216 and 218. Once the network address is obtained, it isreturned to the common channel distributor to continue SCCP processing,as shown in block 220 (FIG. 3) and block 240 (FIG. 4) and to continuewith message transfer part routing, as shown in block 222 (FIG. 3) andbloc 242 (FIG. 4).

To provision application location register routing on system 60, servicemanagement system commands are routed to workstation 130 inadministration cluster 70 (FIG. 2) and ethernet controller 128. Aprocessor in administration cluster 70, such as traffic metering andmeasurement processor 126 may then broadcast the updates to distributedSS7 service processor pairs 106 and store the update information in thedatabases or tables therein.

Constructed in this manner, the wireless PCS network may supportmultiple home location register, short message service center, and voicemail service platforms while minimizing the impact on mobile switchingcenter nodes. The mobile customer initiated service queries are locatedand routed to the proper destination to update the mobile customer'slocation, send routing information, and forward short message. Thisenables mobile service providers the capability to expand the databasecapacities by adding multiple platforms to meet the rapid growth insubscriber numbers. Further, it may be seen that application locationregister routing is accomplished at the signal transfer point, which isonly “one hop” away from the mobile switching centers. This dramaticallycuts down on the number of SS7 links the query messages and destinationresponses must travel on to achieve application location registerrouting.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, mutations,substitutions and alterations can be made therein without departing fromthe spirit and scope of the invention as defined by the appended claims.

1. A signal transfer point for use in a mobile telecommunicationsnetwork, inducing responding to a query message, comprising: a firstprocessor operable to obtain from the query message an identifier for aspecific mobile subscriber; an application location register routingdatabase in the signal transfer point, appropriate to be searched forthe identifier so as to determine a network address of a network nodeassociated with the specific mobile subscriber; and a second processoroperable to access the application location register routing database,based at least partially on information in the query message, and searchfor the identifier and determine the network address, to enable thequery message to be forwarded for further processing by the network nodeassociated with the specific mobile subscriber.
 2. The signal transferpoint of claim 1, further comprising a link operable to forward thequery message for further processing by the network node associated withthe specific mobile subscriber.
 3. The signal transfer point of claim 1,wherein the network node comprises a home location register.
 4. Thesignal transfer point of claim 1, wherein the network node comprises ashort message service center.
 5. The signal transfer point of claim 1,wherein the network node is for a service associated with the specificmobile subscriber.
 6. The signal transfer point of claim 1, in which theinformation in the query message includes a translation type.
 7. Thesignal transfer point of claim 1, wherein the application locationregister routing database comprises a table.
 8. The signal transferpoint of claim 1, wherein the network address comprises a global titletranslation destination network address.
 9. The signal transfer point ofclaim 1, wherein the identifier comprises at least a portion of an IMSIsufficient to identify the specific mobile customer in the network. 10.The signal transfer point of claim 1, wherein the identifier comprisesat least a portion of an MSISDN sufficient to be identified with thespecific mobile customer in the network.
 11. The signal transfer pointof claim 1, wherein the first processor is operable to include SCCPprocessing to obtain from the query message the identifier.
 12. A methodof processing a query message in a signal transfer point of a mobiletelecommunications network comprising: obtaining from the query messagean identifier for a specific mobile subscriber; based at least partiallyon information in the query message, accessing an application locationregister routing database in the signal transfer point, appropriate tobe searched in relation to the query message; searching the applicationlocation register routing database for the identifier; determining, bythe searching for the identifier, a network address of a network nodeassociated with the specific mobile subscriber; and forwarding the querymessage to the network node associated with the specific mobilesubscriber for further processing.
 13. The method of claim 12, whereinthe network address comprises a global title translation destinationnetwork address.
 14. The method of claim 12, wherein the identifiercomprises at least a portion of an IMSI sufficient to identify thespecific mobile customer in the network.
 15. The method of claim 12,wherein the identifier comprises at least a portion of an MSISDNsufficient to be identified with the specific mobile customer in thenetwork.
 16. The method of claim 12, wherein the obtaining stepcomprises SCCP processing.
 17. The method of claim 12, wherein thenetwork node comprises a home location register.
 18. The method of claim12, wherein the network node comprises a short message service center.19. The method of claim 12, wherein the network node is for a serviceassociated with the specific mobile subscriber.
 20. The method of claim12, in which the information in the query message includes a translationtype.
 21. The method of claim 12, wherein the step of searching theapplication location register routing database comprises searching atable.